Experimental Observation Techniques And Quantitative Analysis Methods Used In Zooplankton Behavioral Ecology

Ecological studies of zooplankton behavior are important in both biology and ecology,and most of the study was conducted from a macro-scale point of view. At the same time, arather mount of research focused on the qualitative description. Observation techniques andquantitative analysis methods play a key role in the whole process of a research. Consideringthe urgent needs of quantitative research methods in laboratory, this paper aims to developexperimental techniques used for measuring ecological behavior of zooplankton. Quantitativeanalysis methods are also carried out for the purpose of the unfolded observation.In this paper, digital holographic technology is applied to support the implementationand development of3D platform for measuring and recording the behavior of zooplankton.Experimental study on the impact of marine diesel oil pollution on zooplankton and responseof zooplankton to flow field are conducted here. Analysis and processing of data obtainedfrom the experiments contribute to interpreting results in the quantitative point of view.As to the diesel-Artemia larvae toxicity test, individual’s moving speed and angle changeare taken as the main parameters. Artemia individual activity has been studied in two aspects,level of moving ability and athletic complexity. Results obtained through analysis andprocessing of the data show that: under normal conditions, the growth of individual Artemiawith time causes enhanced activity and increases speed. The average speed from the start timeis2.47mm/s and rises to3.72mm/s12hours later, and the corresponding rate of increase is upto51%. Conversely, under diesel conditions, Artemia individual activity is significantlyweakened and the movement speed is reduced accordingly due to the lengthened poisoningtime. Combining the measured experimental data and the impact of the acclimatization periodprior to the experiment, the average speed is2.37mm/s, the value is only1.42mm/s after12hours—decreased by40%. Compared with the normal condition, the average speed ofArtemia individual in diesel polluted seawater12hours later is62percent lower. Consideringthe impact of diesel on the angle changes of Artemia larvae, analysis results show that: undernormal conditions, angle change has the same trend with that of the speed as time increases.The average value is25degrees and rises to37degrees12hours later. Under dieselconditions, with deepen toxic effects with time, Artemia individual angle change is significantly reduced generally despite a small number of large angle changes. The averagevalue is30degrees and rises to21degrees12hours later.Considering both speed and angle change, we can know the impact of diesel on Artemia:as poisoning time increase, Artemia athletic ability is weakened, the complexity of themovement although is lower than that of normal condition, but also increase a little.Experimental study on the toxicity of this work is to quantify the response of zooplankton andto provide a reference for other related test.Artemia behavior in vortex field experiments mainly focuses on changes in thedistribution and direction of individuals. Artemia distribution within the hydrostaticenvironment mainly concentrates in the upper part, corner and close-to-side walls of thecontainer. Analyze its distribution in the various regions: Compared to other regions, the levelof oxygen in the upper part is more adequate; due to Artemia individuals’ hydraulicdisturbances, the heavy algae particles gathered at the corner position; due to the largernumber of individual, the process of Artemia individuals seeking greater freedom is stoppedby the limits of container size and then forms in the side wall near the aggregation. Thedistribution of Artemia in vortex field is uniform in the overall presentation. After analysis,the homogenizing effect of vortex is the main cause; there are other reasons such as weakindividual activities of zooplankton and the corresponding limited resistance to the flow field.In particular, due to the presence of the dead area at the corner of the flow field, almost seenno distribution of Artemia. Consolidated results of two different sets of flow field conditionscan be drawn: Compared hydrostatic environment, both the distribution and direction ofArtemia is relatively universal in vortex field. As a preliminary exploration, this experimentfocuses on quantitative analysis of zooplankton and its interaction with the flow field, layingthe foundation for more in-depth study carried out in the future.